1. Field of the Invention
The present invention relates to a water supply control apparatus, and more particularly to a water supply control apparatus having a battery as a power supply for controlling the supply of water to a flushing device.
2. Description of the Prior Art
Known water supply control apparatus having a battery as a power supply for automatically controlling the supply of water to a flushing device such as a flush toilet or a wash bowl include a sensor for controlling the water supply by sensing the user who is approaching or using the flushing device. For example, Japanese Laid-Open Patent Publication No. 59-126831 published July 21, 1984 discloses a toilet flushing apparatus which essentially includes a sensor unit comprising a light-emitting element for emitting infrared radiation at all times and a light detector element, an electric circuit, a solenoid-operated valve for supplying water, and a battery as a power supply for driving the various components. The sensor unit is in the form of a photoelectric sensor of the diffused reflection type in which several thousands of pulses of infrared radiation are generated by the light-emitting element per second, and the light detector element detects infrared radiation pulses reflected from the user of the toilet for producing a sensor signal.
Since the sensor unit continuously emits infrared rays at all times, it consumes a large amount of electric power and hence the power supply battery is required to be replaced frequently as its service life is generally short. Such frequent battery replacement is awkward and uneconomical.